GB/T 4074.3-1999 Winding wire test methods Part 3: Mechanical properties
Some standard content:
GB/T4074.1~4074.6—1999
This standard is equivalent to the International Electrotechnical Commission (IEC) standard IEC60851 "Winding Wire Test Method" series of standards. This series of standards are:
IEC60851-1:1996
IEC60851-2:1996
IEC60851-3.1996
IEC60851-4:1997
IEC60851-5.1996
IEC60851-6:1996
Winding Wire Test Method Test methods
Part 1: General provisions
Test methods for winding wires
Part 2: Dimensional measurement
Test methods for winding wires
Part 3: Mechanical properties
Test methods for winding wires
Part 4: Chemical properties
Test methods for winding wires Part 5: Electrical properties Test methods for winding wires
Part 6: Thermal properties||t t||Corresponding to the IEC60851 series of standards, this standard is divided into the following parts under the general title of "Test methods for winding wires": Test methods for winding wires Part 1: General provisions GB/T4074.1—1999
GB/T4074.2—1999
Test methods for winding wires Part 2: Dimensional measurement GB/T4074.3—1999
Test methods for winding wires Part 3: Mechanical properties Test methods for winding wires Part 4: Chemical properties GB/T4074.4—1999
GB/T4074.5—1999
Test methods for winding wires Part 5: Electrical properties GB/T4074.6—1999
Test methods for winding wires Part 6: Thermal properties Parts 2, 3, 4, 5 and 6 should be used together with Part 1. According to the provisions of GB/T1.1-1993 and the first amendment (1995), the foreword of the adopted object should be retained when adopting an international standard. Since the IEC60851 standard consists of 6 parts, all 6 parts have a foreword. Therefore, they are combined into the "IEC Foreword" of this standard. The "Introduction" of each part is also combined into the IEC Introduction of this standard. In addition, some editorial errors in IEC60851 were corrected when formulating this standard.
This standard cancels GB/T4074.15-1983\Reciprocating paint scraping test method", GB/T4074.18-1983\Breakdown voltage aluminum foil method", GB/T4074.28-1983 trichloroethylene and methanol extraction method", GB/T4074.30-1983\Chlorodifluoromethane solvent method" and GB/T4074.31-1983\Chlorodifluoromethane foaming method". This standard adds the self-adhesive layer thickness of enameled round wire, the bonding strength of twisted coils and the friction test methods. This standard revises GB/T4074.23-1983 "Test method for resistance to water-containing transformer oil". This standard retains the type test (T), extraction test (T) and extraction test (T) in GB/T4074.1-1983. The definitions of sample test (S) and routine test (R) are used to facilitate the implementation of the enameled wire product standard. Since the first amendment to IEC60172 (1998) has specified the temperature index determination method for enameled flat wire and film wrapped wire, the test method 15 "Temperature Index" in Part 6 "Thermal Properties" of this standard has been modified accordingly. This standard replaces GB/T4074-1983 and GB/T1343-1984 standards from the date of implementation. The appendices to this standard are all suggestive appendices. This standard was proposed by the State Bureau of Machinery Industry. This standard is under the jurisdiction of the National Technical Committee for Standardization of Wires and Cables. The main drafting units of this standard: Shanghai Cable Research Institute, Fuzhou Datong Electromechanical Co., Ltd., Tongling Jingda Copper Materials Group Co., Ltd., Zhengzhou Electromagnetic Wire Factory, Hengyang Instrument Machinery Factory. The main drafters of this standard: Chen Huimin, Shu Yingchun, Zheng Qirong, Zhu Qiang, Hu Jie, Yin Yuelu. 1
GB/T4074.14074.6—1999
IEC Foreword
1.IEC (International Electrotechnical Commission) is an international standardization organization composed of national electrotechnical committees (IEC National Committees). The purpose of EC is to promote international cooperation on all issues of standardization in the electrical and electronic fields. To achieve this purpose, in addition to organizing various activities, EC also publishes international standards and entrusts technical committees to formulate these standards. Any national committee interested in a certain standard may participate in the formulation of the standard. 2. Technical Committee IEC formal resolutions or agreements drawn up on behalf of the National Committees on technical issues of particular concern to them express as far as possible the international consensus on these issues. 3 These resolutions or agreements are published in the form of standards, technical reports or guidelines, which are used internationally in the form of recommended documents and are recognized by the National Committees in this sense. 4 In order to promote international unification, the IEC National Committees frankly adopt IEC International Standards in their countries and regions to the greatest extent possible. Any differences between EC standards and corresponding national or regional standards should be clearly pointed out in the national or regional standards. 5. IEC does not provide a marking method to indicate IEC approval, nor does IEC assume responsibility for any equipment that claims to comply with the requirements of a standard.
6. It must be noted that some of the contents of this international standard may be subject to patent rights. IEC shall not be responsible for identifying any or all such patent rights.
International Standard IEC60851-160851-6 was prepared by IEC Technical Committee 55 "Winding Wire". The second edition of IEC60851-1 standard cancels and replaces the first edition of 1985 and makes technical revisions. The text of this standard is based on the following documents: FDIS Documents
55/470A/FDIS
Voting Report
55/511/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. Appendix A is an informative appendix only.
The second edition of IEC60851-2 standard cancels and replaces the first edition published in 1985 and Amendment No. 1 (1992), and is technically revised.
The text of this standard is based on the following documents: FDIS Documents
55/471A/FDIS
Voting Report
55/512/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. The first amendment to IEC60851-2 is based on the following documents: FDIS Document
55/587/FDIS
Voting Report
55/605/RVD
All information on the voting to approve this standard can be found in the "Voting Report" listed in the table above. 1
GB/T4074.1~4074.6—1999
The second edition of IEC60851-3 standard cancels and replaces the first edition published in 1985 and its first and second amendments (1992), and makes technical revisions.
The text of this standard is based on the following documents:FDIS Document
55/472A/FDIS
Voting Report
55/513/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. Appendices A and B are only informative appendices. Amendment No. 1 to IEC60851-3 is based on the following documents:FDIS Document
55/592/FDIS
Voting Report
55/612/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. The second edition of IEC60851-4 standard cancels and replaces the first edition published in 1985 and its amendment No. 1 (1992), and makes technical revisions.
The text of this standard is based on the following documents: FDIS Documents
55/473A/FDIS
Voting Report
55/514/RVD
Full information on the voting and approval of this standard can be found in the "Voting Report" listed in the table above. Amendment No. 1 to IEC60851-4 is based on the following documents: FDIS Documents
55/597/FDIS
Voting Report
55/614/RVD
Full information on the voting and approval of this standard can be found in the "Voting Report" listed in the table above. IEC60851-4 Amendment No. 2.The first edition is a combination of the second edition of EC60851-4 (1996) and its first amendment (1997). The third edition of IEC60851-5 standard cancels and replaces the second edition published in 1988 and its first amendment (1990), and makes technical revisions.
This standard text is based on the following documents: FDIS document
55/474A/FDIS
Voting report
55/515/RVD
Full information on the voting to approve this standard can be found in the "Voting Report" listed in the table above. The first amendment to IEC60851-5 is based on the following documents:1
GB/T4074.1～4074.6—1999
FDIS DocumentbZxz.net
55/542/FDIS
Voting Report
55/572/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. The second edition of IEC60851-6 standard cancels and replaces the first edition published in 1985 and makes technical revisions. The text of this standard is based on the following documents:FDIS Document
55/475A/FDIS
Voting Report
55/516/RVD
Full information on the voting for the approval of this standard can be found in the "Voting Report" listed in the table above. Appendix A is an informative appendix only.
The first amendment to IEC60851-6 is based on the following documents:FDIS Document
55/561/FDIS
Voting Report
55/593/RVD
All information on the voting to approve this standard can be found in the "Voting Report" listed in the table above. N
GB/T4074.14074.6—1999
GB/T4074.1~4074.6 is a part of the series of standards for insulated wires for windings of electrical equipment. This series of standards consists of 3 parts:
a) Test methods (GB/T4074);
b) Product standards (IEc60317);
c) Packaging (JB/T8135).
1 Scope
National Standard of the People's Republic of China
Test methods for winding wiresPart 3: Mechanical propertiesThis standard specifies the following test methods:
-Test method 6: Elongation
-Test method 7: Rebound resilience
-Test method 8: Flexibility and adhesion
-Test method 11: Scratch resistance
-Test method 18: Thermal bonding and solvent bondingGB/T4074.3—1999
idtIEC60851-3:1996
AmendmentNo.1:1997
Replace GB4074.3~4074.10—1983
GB4074.14—1983
GB4074.27—1983
GB1343.3~1343.7-1984
For definitions, general principles of test methods and a list of winding wire test methods, please refer to GB/T4074.1. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T4074.1—1999 Test methods for winding wires Part 1: General provisions (idtIEC60851-1:1996) GB/T4074.2—1999 Test methods for winding wires Part 2: Dimensional measurement (idtIEC60851-2:1996) GB/T4074.5—1999 Test methods for winding wires Part 5: Electrical properties (idtIEC60851-5:1996) GB/T3048.2-1994 Test methods for electrical properties of wires and cables: Test resistivity of metallic conductor materials IEC1033:1991 Test method for determining the bond strength of impregnants for enameled wires ISO178:1993 Plastics—Test methods for flexural properties 3 Test method 6: Elongation
3.1 Elongation at break
Elongation is the ratio of the increase in length to the original length, expressed as a percentage. On an extensometer or tensile testing machine, stretch a straightened specimen with a free test length of 200mm to 250mm to the conductor breaking point at a rate of (5 ± 1) mm/s, and calculate the ratio of the linear length increment to the free test length at the time of breaking, expressed as a percentage. Measure 3 specimens, record 3 test values, and take the average value as the elongation at break. 3.2 Tensile strength
Tensile strength is the ratio of the breaking force of the conductor to its original cross-section when it breaks. Instructions for use:
1 The added note to this clause is for ease of use and shall be supplemented accordingly in the referenced standard. Approved by the State Administration of Quality and Technical Supervision on November 11, 1999, and implemented on May 1, 2000
GB/T4074.3—1999
On a tensile testing machine, stretch a straightened specimen with a free test length of 200mm to 250mm to the conductor breaking point at a rate of (5±1) mm/s, and record the breaking force at the time of breaking. Measure 3 specimens, record the original cross-section and the 3 breaking force test values, and take the average value of the ratio of the breaking force to the original cross-section as the tensile strength.
Note: The original cross-section is measured in accordance with Article 6.6 of GB/T3048.2—1994. 4 Test method 7: Rebound resilience
Rebound resilience is the angle measured after the specimen wound into a spiral coil or bent into an angle rebounds. 4.1 Conductor Round wire with nominal diameter of 0.080 mm or more and 1.600 mm or less 4.1.1 Test principle
-A straightened specimen is wound 5 times on a round bar. The diameter of the round bar and the tension during winding shall comply with the provisions of the relevant product standards. The rebound resilience measurement is the angle reading of the rebound at the end of the fifth turn of the specimen. 4.1.2 Test equipment
An example of the test equipment is shown in Figure 1. The structure and dimensions of the round bar are shown in Figure 2 and Table 1. The spiral groove in Figure 2 can facilitate winding, but it is not mandatory to use it. The scale is marked with 72 equal divisions, so the reading is the degree of rebound of each turn of the 5-turn specimen. Table 1 Round bar for rebound resilience test
Rod diameter \
1) If it is a spiral groove, it is the groove bottom width. 2) See Figure 2.
4.1.3 Test procedure
Dimensions\, mm
Install and lock a round bar of the specified size on the test equipment in a position horizontal to its axis. The slot or hole for fixing the specimen should be aligned with the zero position of the dial. Apply some talcum powder to the round bar to prevent the enameled wire from sticking. Hang the specified load on one end of the straightened specimen, which is about 1 m long. Loosen the handle for rotating the round bar and insert the other end of the specimen into the fixing slot or fixing hole of the round bar so that a sufficient length of the specimen extends out of the other side of the round bar, so that the specimen is close to the round bar. Slowly lower the load so that the specimen hangs vertically under the round bar. The zero position of the scale and the fixing slot or fixing hole are also vertically downward. Fix the free end of the specimen and rotate the round bar counterclockwise for 5 full turns or more (see the dial) until the zero position of the dial is vertically upward, and then lock the handle. Keep the specimen in position on the round bar and remove the load. Then cut the specimen about 25 mm beyond the end of the fifth turn. The end should be bent into a vertical position to coincide with the zero position of the dial, which serves as a pointer. Place a pencil or similar tool on the left side of the end of the specimen to prevent the specimen from suddenly rebounding. Then slowly loosen the coil without jumping.
Note: If the specimen rebounds suddenly, erroneous results may be obtained. Loosen the locking device of the round bar and the dial and turn it clockwise. Make the pointer vertically upward. The dial reading indicated by the pointer is the rebound angle 2
GB/T4074.3—1999
If the enameled wire is very elastic, the pointer may rebound more than one full circle. In this case, add 72 to the dial reading for each full circle of rebound. Measure 3 specimens, record 3 readings, and take the average value as the rebound angle. 4.2 Round and flat wires with a nominal conductor diameter of more than 1.600mm 4.2.1 Test principle
A straightened specimen should be bent into 30°, and the angle reading of the enameled wire rebounding after the force is removed is the rebound angle. 4.2.2 Test equipment
An example of a test equipment is shown in Figure 3. Its basic components include: a fixed clamp (2), a movable clamp (1) and a sector-shaped scale (5), with units (). The scale of the scale is in increments of 0.5° in the range of 0° to 10°. The sector-shaped scale is in the shape of an arc and is placed on a plane 90° to the clamp surface. Its center (3) is at the outer edge of the fixed clamp. The handle can be moved on the sector-shaped scale in a vertical plane, and its fulcrum is located at the center of the arc of the scale.
The handle should have a pointer or mark to correctly read the rebound angle. The handle is about 305 mm long and has a millimeter scale starting at the center of the arc-shaped scale. There is a slider with a knife edge (4) on the handle. 4.2.3 Preparation of specimens
The specimen is at least 1200 mm long. When it is removed from the wire drum, it should be bent as little as possible, and then the specimen is straightened by hand and cut into three specimens of 400 mm in length. No tool should be used for stretching, and unnecessary bending should be avoided to avoid hardening of the specimen. 4.2.4 Test procedure
The position of the slider on the handle should be 40 times the diameter of the conductor or the narrow side dimension of the conductor. Tighten the specimen between the two clamps until it just prevents slipping. The direction of tensioning the specimen should be the same as the direction of winding it on the wire drum. The free end of the specimen should extend (12±2) mm beyond the slider blade. From the starting point (30° scale, position 1), use the handle to bend the specimen 30 (0° scale, position 2). The bending time should be controlled within 2s~5s. The specimen should be kept in position 2 for a maximum of 2s, and then the handle is withdrawn in the opposite direction at the same angular speed until the slider blade slides off the specimen. Move the handle again until the slider blade just touches the specimen without bending the specimen. The reading of the handle pointer (position 3) on the sector scale is the springback angle.
Measure 3 specimens, record 3 readings, and take the average value as the springback angle. 5 Test Method 8: Flexibility and Adhesion
Flexibility and adhesion reflect the ability of the winding wire to withstand external forces such as stretching, winding, bending or twisting without cracking or losing adhesion.
5.1 Round Rod Winding Test
5.1.1 Round Wire
A straightened specimen is wound tightly and continuously for 10 turns on a polished round rod, the diameter of which is specified in the relevant product standard. The round rod is wound at a speed of 1r/s to 3r/s, and the tension on the wire during winding is just enough to make the wire contact the round rod to avoid stretching and twisting of the wire. Any equipment that meets the above requirements may be used.
5.1.1.1 If the product standard stipulates that enameled round wire with a conductor nominal diameter of 1.600mm or less should be pre-stretched before winding, the specimen should be stretched to the specified percentage according to Article 3. After winding, use a magnifying glass with a magnification as specified in Table 2 to check for cracking.
Measure 3 specimens. Any cracks found shall be recorded in the report. 5.1.1.2 After winding fiber-coated round wire
, check the specimen with normal vision or a magnifying glass of 6 times or less to see if the bare conductor is exposed. Measure 3 specimens. Exposed bare conductors shall be recorded in the report. 5.1.1.3 After winding fiber-coated enameled round wire
, check the specimen with normal vision or a magnifying glass of 6 times or less to see if the bare conductor or primer layer is exposed. Measure 3 specimens. Exposed bare conductors or primer layers shall be recorded in the report. 3
1) 1 times means using normal vision.
5.1.1.4 Film wrapped round wire
GB/T4074.3—1999
Table 2 Magnification for crack inspection
Conductor nominal diameter, mm
and below
After winding, use normal vision or a magnifying glass of 6 times or less to check whether the sample is exposed to bare conductor or delamination. Measure 3 samples. Exposure of bare conductor or delamination should be recorded in the report. 5.1.2 Flat wire
Magnifying glass power)
10~15 times
6~10 times
1~6 times
A straightened sample of about 400 mm in length is bent 180° in each direction on a polished round bar to form an elongated S shape. The diameter of the round bar is specified in the relevant standards. The straight section between the U-bends is at least 150 mm. Care should be taken to ensure that the specimen is not warped and the bend is flat. Suitable test equipment is shown in Figure 4.
After bending, use a 6-10x magnifying glass to check: if it is an enameled wire, check whether it is cracked; if it is a fiber-coated wire, check whether the conductor or primer layer is exposed; if it is a film-wrapped wire, check whether the conductor is exposed or delamination. Bend 6 specimens, including 3 wide-side bends (along the narrow side dimension) and 3 narrow-side bends (along the wide side dimension). If the specimen has cracks, delamination, exposed conductors or primer layers, they should be recorded in the report. 5.1.3 Coated wire bundles
A straightened specimen is wound continuously on a polished round rod for 10 turns. The diameter of the round rod is specified in the relevant product standard, and the tension is in accordance with the provisions of Article 3.2.5.3 of GB/T4074.2-1999. It should be noted that the specimen should not be twisted during each winding. After winding, use normal vision to check whether the coating of the specimen is open. Measure one sample. If the tightness of the coating does not meet the requirements, it should be recorded in the report. 5.2 Tensile test (applicable to enameled round wires with a nominal conductor diameter of 1.600mm or more) A straightened sample should be stretched to the percentage specified in the relevant product standard according to the provisions of Article 3. After stretching, use normal vision or a magnifying glass of less than 6 times to check whether the sample is cracked or loses adhesion. Measure 3 samples. If the sample is cracked and (or) loses adhesion, it should be recorded in the report. 5.3 Snap-break test (applicable to enameled round wires with a nominal conductor diameter of 1.000mm and below) A straightened sample should be quickly stretched to the breaking point or the percentage specified in the relevant product standard. The test equipment is shown in Figure 5, and its free test length is 200mm~250mm. After stretching, use a magnifying glass with a magnification as specified in Table 2 to check whether the sample is cracked or loses adhesion. No assessment is made within 2mm of the broken end.
Measure 3 samples. If the sample is cracked and (or) loses adhesion, it should be recorded in the report. 5.4 Stripping test (applicable to enameled round wire with a conductor nominal diameter of more than 1.000 mm) A straightened specimen shall be placed on the test equipment shown in Figure 6, with two fixtures located on the same axis and 500 mm apart. One of them can rotate, while the other cannot but can be moved axially and loaded, and tension is applied to twist the specimen. The load is specified in Table 3. Use a scraper as shown in Figure 7 to scrape the paint film on both sides of the specimen axially until the conductor is exposed, as shown in Figure 8. The pressure of the scraper should be sufficient to scrape off the paint film and leave a clean and smooth surface at the interface between the paint film and the conductor, but not to scrape off too much conductor material. Peel off the paint film from two locations 10 mm away from the fixture. The starting speed of the rotating equipment should be 60 r/min to 100 r/min until the number of revolutions R specified in the relevant product standard is reached. After stripping and twisting, the specimen should be checked for loss of adhesion. If the paint film can be peeled off the specimen without difficulty (for example, with a fingernail), it should be considered to have lost adhesion even if it cannot be completely separated. Measure one specimen and record the loss of adhesion in the report. 5.5 Adhesion test
GB/T4074.3—1999
-A straightened specimen of about 300 mm in length shall be stretched to the percentage specified in the relevant product standard in accordance with the provisions of Article 3.1. Table 3 Load for peeling test
Conductor nominal diameter, mm
5.5.1 Enameled rectangular wire
and below
Before stretching, the specimen shall be cut in the middle of the measuring length until the conductor. After stretching, the specimen shall be checked for loss of adhesion. Measure 1 specimen, and if there is loss of adhesion, it shall be recorded in the report. And measure the loss of adhesion distance in one direction from the cutting point. Measure the loss of adhesion distance on each side of the specimen and record the maximum value. 5.5.2 Impregnated fiber-covered round and rectangular wires
Before stretching, remove all insulation from the specimen but retain the insulation in the middle 100 mm. After stretching, the specimen shall be checked for loss of adhesion.
Measure one specimen and record any loss of adhesion in the report. Loss of adhesion is considered to occur if the insulation of round wire slips on the conductor or if the insulation of flat wire separates on one or both sides of the specimen. 5.5.3 Fiber-coated enameled round and flat wires
Before stretching, the specimen shall be cut once around the conductor at two locations 100 mm apart in the middle of the measuring length. After stretching, check if the specimen has lost adhesion.
Measure one specimen and record any loss of adhesion in the report. 5.5.4 Film-wound round and flat wires
Before stretching, the specimen shall be cut once around the conductor in the middle of the measuring length. After stretching, check if the specimen has lost adhesion. Measure one specimen and record any loss of adhesion in the report. Measure the loss of adhesion distance in one direction from the cut point. Measure the loss of adhesion distance on each side of the specimen and record the maximum value. 6. Test method 11: Scratch resistance (applicable to enameled round wire) Scratch resistance is expressed by the maximum scratching force that the enameled wire can withstand when a scraper needle is scraped with increasing pressure. 6.1 Test Principle
A straightened specimen is subjected to a unidirectional paint scraping test. The surface of the enameled wire is scraped with a needle and the load on the needle is continuously increased. The force that causes the needle to make electrical contact with the conductor is the scraping force.
6.2 Test Equipment
The test equipment shown in Figure 9 should be used. Its mechanical device should be able to generate a unidirectional scraping force at a rate of (400±40) mm/min. The paint scraping device should include a polished piano wire or a needle with a diameter of (0.23±0.01) mm, placed between two clamps. The clamps can firmly clamp the piano wire or needle without causing it to sag or bend and at right angles to the paint scraping direction. The paint scraping direction is the axial direction of the enameled wire. To place the specimen, the test equipment should have two clamps on the support table, which can be lowered when the specimen is inserted between the clamps and straightened. The test equipment should be able to generate a DC voltage of (6.5±0.5) V, which is applied between the conductor and the piano wire or scraping needle. A series resistor or relay can be used to limit the short-circuit current to 20 mA. The circuit should be able to detect the short-circuit current and stop scraping when the scraper needle scrapes about 3 mm of the conductor.
There should be a scale on the lower edge of the lever of the test equipment. The coefficient indicated multiplied by the starting load is the scraping force. 5
6.3 Test procedure
GB/T4074.3—1999
A specimen straightened with a maximum elongation of 1% is wiped clean and placed in the test equipment. The specimen is then fixed with a chuck and the support table is adjusted to contact the specimen.
The initial force applied to the paint scraping device should not be greater than 90% of the minimum scraping force specified in the relevant product standards, and a short circuit should be made between the scraper needle and the conductor, with the short circuit point between 150 mm and 200 mm from the fixed support point. The loaded paint scraping device should be slowly lowered to the surface of the enameled wire and then the paint scraping should be started.
When the scraper stops scraping the paint, read the coefficient at this time from the scale on the lower edge of the lever. Record the product of this coefficient and the initial force. The test should be repeated twice on the same sample, once at 120° and once at 240° from the original position. Record the test results.
Measure 1 sample. Record 3 test values. Take the average as the average scratching force. 7 Test method 18: Thermal bonding and solvent bonding 1) (Applicable to enameled round wires with a conductor nominal diameter of 0.050 mm or more and 2.000 mm or less)
Thermal bonding and solvent bonding reflect the ability of coil windings to be bonded together under the action of heat and solvent. 7.1 Bonding force of vertical spiral coils
The bonding force of vertical spiral coils reflects the ability to maintain bonding when a load is applied to the lower end of the bonded coil. 7.1.1 The test method for conductors with a nominal diameter of 0.050 mm or less shall be determined by negotiation between the supplier and the buyer. 7.1.2 Conductor nominal diameter 0.050 mm or more and 2.000 mm or less 7.1.2.1 Test principle
The coil is wound on a round bar into a spiral coil, then pressed with a load and bonded under the action of heat and solvent. After bonding, the coil sample is removed from the round bar and hung vertically, and a load is hung on its lower end to determine whether the sample can withstand the specified load. Repeat the test at elevated temperature. 7.1.2.2 Sample preparation
A straightened sample is wound on a polished round bar with a diameter as specified in Table 4. The minimum length of the coil is 20 mm. The winding rate is controlled between 11/s and 3/s under the condition that the tension during winding does not exceed the value specified in Table 4. To facilitate the free release of the coil, the end of the sample should not be fixed. The coil on the round bar should be placed vertically as shown in Figure 10a, and the load should be applied as specified in Table 4. The weight should not stick to the round bar, and there should be a gap between them. The device is then placed in a forced-air oven at a temperature in accordance with the relevant product standards for a period of 30 minutes for enameled wires with a nominal conductor diameter of 0.710 mm or less; or 1 hour for enameled wires with a nominal conductor diameter of 0.710 mm or more and 2.000 mm or less, unless otherwise agreed between the supplier and the buyer. After cooling to room temperature, the coil is removed from the round bar. Table 4 Preparation of spiral coils
Conductor nominal diameter, mm
and below
1) This test will be extended to solvent-bonded enameled wires. Round bar diameter
Maximum tension during winding
Load applied to the coil during bonding
2) For enameled wires with larger diameters, steel rods are suitable. For enameled wires with smaller diameters, copper rods are used, as they can be stretched to reduce the diameter and facilitate the removal of the coil.
Conductor nominal diameter, mm
and below
7.1.2.3 Test procedure at room temperature
GB/T4074.3—1999
Table 4 (end)
Rod diameter
Maximum tension during winding
Load applied to coil during bonding
Hang the coil sample at one end as shown in Figure 10b, and apply the load specified in the relevant product standard to the other end. The load should be applied in a manner that avoids any additional impact.
Measure 3 samples. If the coil is separated (except the first and last turns), it should be recorded in the report. The temperature of the bonded coil should also be recorded.
7.1.2.4 Test procedure at high temperature
Hang the coil sample at one end as shown in Figure 106, and apply the load specified in Table 5 to the other end. The load should be applied in a manner that avoids any additional impact. Place the loaded specimen in a forced ventilation oven for 15 minutes at a temperature in accordance with the relevant product standards. Measure 3 specimens. If the coil separates (except for the first and last turns), this should be recorded in the report. The temperature of the bonded coil should also be recorded.
5 Adhesion at high temperature
Nominal diameter of conductor, mm
and below
Bond strength of twisted coil
Bond strength is the maximum force required to destroy the twisted coil. 7.2.1 Test principle
Nominal diameter of conductor, mm
and below1.2.2 Preparation of specimens
A straightened specimen is wound on a polished round bar with a diameter as specified in Table 4. The minimum length of the coil is 20 mm. The winding rate is controlled between 11/s and 3/s, provided that the tension during winding does not exceed the value specified in Table 4. The end of the specimen should not be fixed to facilitate free unwinding of the coil. The coil on the round bar should be placed vertically as shown in Figure 10a and the load should be applied as specified in Table 4. The weight should not stick to the round bar and there should be a gap between them. The device is then placed in a forced ventilation oven at a temperature as specified in the relevant product standards for a placement time of: 30 min for enameled wires with a conductor nominal diameter of 0.710 mm and below; - 1 h for enameled wires with a conductor nominal diameter of 0.710 mm or above and 2.000 mm or below, unless otherwise agreed between the supplier and the buyer. After cooling to room temperature, the coil is removed from the round bar. Table 4 Preparation of spiral coils
Conductor nominal diameter, mm
and below
1) This test will be extended to solvent bonded enameled wires. Round rod diameter
Maximum tension during winding
Load applied to the coil during bonding
2) For enameled wires with larger diameters, a steel rod is suitable. For enameled wires with smaller diameters, a copper rod is used because the copper rod can be stretched to reduce the diameter and facilitate the removal of the coil.
Conductor nominal diameter, mm
and below
7.1.2.3 Test procedure at room temperature
GB/T4074.3—1999
Table 4 (end)
Round rod diameter
Maximum tension during winding
Load applied to the coil during bonding
Hang one end of the coil specimen as shown in Figure 10b, and apply the load specified in the relevant product standard to the other end. The load shall be applied in such a way as to avoid any additional impact.
Measure 3 specimens. If the coil separates (except the first and last turns), this shall be recorded in the report. The temperature of the bonded coil shall also be recorded.
7.1.2.4 Test procedure at elevated temperatures
Hang the coil specimen at one end as shown in Figure 106 and apply a load as specified in Table 5 to the other end. The load shall be applied in such a way as to avoid any additional impact. Place the loaded specimen in a forced-air oven for 15 min at a temperature as specified in the relevant product standard. Measure 3 specimens. If the coil separates (except the first and last turns), this shall be recorded in the report. The temperature of the bonded coil shall also be recorded.
5 Bond strength at elevated temperatures
Conductor nominal diameter, mm
and below
Bond strength of twisted coils
Bond strength is the maximum force required to break a twisted coil. 7.2.1 Test principle
Conductor nominal diameter, mm
and below1.2.2 Preparation of specimens
A straightened specimen is wound on a polished round bar with a diameter as specified in Table 4. The minimum length of the coil is 20 mm. The winding rate is controlled between 11/s and 3/s, provided that the tension during winding does not exceed the value specified in Table 4. The end of the specimen should not be fixed to facilitate free unwinding of the coil. The coil on the round bar should be placed vertically as shown in Figure 10a and the load should be applied as specified in Table 4. The weight should not stick to the round bar and there should be a gap between them. The device is then placed in a forced ventilation oven at a temperature as specified in the relevant product standards for a placement time of: 30 min for enameled wires with a conductor nominal diameter of 0.710 mm and below; - 1 h for enameled wires with a conductor nominal diameter of 0.710 mm or above and 2.000 mm or below, unless otherwise agreed between the supplier and the buyer. After cooling to room temperature, the coil is removed from the round bar. Table 4 Preparation of spiral coils
Conductor nominal diameter, mm
and below
1) This test will be extended to solvent bonded enameled wires. Round rod diameter
Maximum tension during winding
Load applied to the coil during bonding
2) For enameled wires with larger diameters, a steel rod is suitable. For enameled wires with smaller diameters, a copper rod is used because the copper rod can be stretched to reduce the diameter and facilitate the removal of the coil.
Conductor nominal diameter, mm
and below
7.1.2.3 Test procedure at room temperature
GB/T4074.3—1999
Table 4 (end)
Round rod diameter
Maximum tension during winding
Load applied to the coil during bonding
Hang one end of the coil specimen as shown in Figure 10b, and apply the load specified in the relevant product standard to the other end. The load shall be applied in such a way as to avoid any additional impact.
Measure 3 specimens. If the coil separates (except the first and last turns), this shall be recorded in the report. The temperature of the bonded coil shall also be recorded.
7.1.2.4 Test procedure at elevated temperatures
Hang the coil specimen at one end as shown in Figure 106 and apply a load as specified in Table 5 to the other end. The load shall be applied in such a way as to avoid any additional impact. Place the loaded specimen in a forced-air oven for 15 min at a temperature as specified in the relevant product standard. Measure 3 specimens. If the coil separates (except the first and last turns), this shall be recorded in the report. The temperature of the bonded coil shall also be recorded.
5 Bond strength at elevated temperatures
Conductor nominal diameter, mm
and below
Bond strength of twisted coils
Bond strength is the maximum force required to break a twisted coil. 7.2.1 Test principle
Conductor nominal diameter, mm
and below
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